A

I'm peering through my new glarses* at the screen. I have been mildly dyslexic for years (my PHD was a disgrace of spelling errors) and came to a climax of gobbledegook before realising that half (but definitely not all) of the problem was my eyesight.
At work, where I teach study skills as well as songwriting, I was hearing my students say over and over again, 'But I just don't see the mistakes!'
Gradually, I started asking them when they had last had their eyes tested, and discovered that quite a lot of them should have been wearing spectacles for reading and writing and weren't, and may of the others had thought their eyesight was getting worse but hadn't done anything about it yet.
So perhaps it's a common problem that contributes to the problems caused by dyslexia. I don't know. But I do know that quite a few eminent academics are dyslexic.
Sometimes, I have to recall blog postings two or three times before I can convince myself that the spelling is correct.

*this one's on purpose. I'm a Geordie who speaks like a Sarf Londoner, apart from my 'a's, which will always be hard and spiky.